Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add melodic-software/claude-code-plugins/plugin install planningWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/melodic-software/claude-code-plugins/design-handoff)<a href="https://agentmods.dev/skills/melodic-software/claude-code-plugins/design-handoff"><img src="https://agentmods.dev/badge/skills/melodic-software/claude-code-plugins/design-handoff/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/melodic-software/claude-code-plugins/design-handoff"><img src="https://agentmods.dev/badge/skills/melodic-software/claude-code-plugins/design-handoff.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00163 | $0.01997 |
| Opus 5.5 | $0.00065 | $0.00799 |
| Sonnet 5.5 | $0.00033 | $0.00399 |
| Haiku 4.5 | $0.00016 | $0.00200 |
Grade A, and why
design-handoff scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 104 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Repository context. Gather first
Collect these with individual Bash calls, one command per call, never combined into a single invocation:
- Current branch,
git branch --show-current
Treat a failure (not a repository, git unavailable) as an unknown value and carry on. Keep these as separate body Bash calls rather than pre-compute lines: the harness runs a skill's whole pre-compute block as one shell invocation, and a worktree-isolated session refuses a compound command that contains git. The dated record for that composition claim is the worktree skill's reference/gather-block.md, "The pre-compute block runs as one shell invocation".
Purpose
The seam between design and planning. /planning:plan's prerequisite check blocks on design-gate evidence; this skill produces that evidence honestly. A binary check read off the artifact, then a handoff summary sourced from the artifacts rather than recalled from conversation memory.
Design artifacts live in <contract_dir>/<topic-slug>/design/ (default docs/topics/). The topic's contract slice on the task branch, joining the memory slice under contract_tier: local; roots, tier, and precedence resolve per the topic-docs binding ${CLAUDE_PLUGIN_ROOT}/reference/topic-docs.md. Derive <topic-slug> from the task or branch name (kebab-case, ≤40 chars; shared with /planning:design and /planning:plan).
Binary gate. Check the artifact, not your memory
Read design-threads.md in the topic's resolved design slice (<contract_dir>/<topic-slug>/design/, default docs/topics/; the memory slice under contract_tier: local) and confirm, thread by thread, that every design thread is one of:
- RESOLVED. The deciding rationale is recorded in the artifact (not merely "decided"), or
- directional. Direction agreed AND the remaining detail carries a research tag, or
- TAGGED-DEFERRED. An explicit research tag naming the external investigation needed.
What ships with it
7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- evals/evals.json 8.5 KB
- evals/fixtures/design-resolution-early-exit.md 783 B
- evals/fixtures/design-threads-all-resolved.md 1.2 KB
- evals/fixtures/design-threads-coverage-all-six.md 2.1 KB
- evals/fixtures/design-threads-coverage-gaps.md 1.5 KB
- evals/fixtures/design-threads-single-gap.md 946 B
- evals/fixtures/design-threads-unresolved-gap.md 967 B
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed · +1 lines e33c34c9e2e7
- 1mo ago Changed · +36 lines · +9 tokens per session eabb8f928f82
- 1mo ago Changed · +8 lines 89cb31ac5fb7
- 1mo ago First seen · 59 lines · 154 tokens per session scan A 00de034173c8
design-handoff is a skill published in the GitHub repository melodic-software/claude-code-plugins (26 stars, last pushed today), licensed MIT. It adds 163 tokens to every session and 1,997 once invoked, about $0.0007 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other skills, from other repositories
parallel-orchestrator
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parallel-worker
Execute focused implementation tasks in a parallel workflow. Use when: working on assigned files in a worktree, making checkpoint commits, signaling dependencies or blockers, completing orchestrator-assigned tasks. Triggers: worker, checkpoint, worktree, assigned scope, commit prefix, parallel task.
optimize-local-search
For NP-hard optimization: TSP, scheduling, assignment problems. Uses greedy construction + local improvement (2-opt, hill climbing).
solve-constraint-puzzle
For constraint satisfaction: Sudoku, scheduling, N-queens, logic puzzles, SAT-like problems, assignment problems. Uses propagate-then-search pattern.
test-with-examples
For example-driven development: test cases as specifications, input/output pairs, documentation through examples.
return-none-for-failure
For graceful failure: return None or False instead of exceptions, let caller decide how to handle failure.